Astronomers have observed an explosion 180 million light years away which challenges our current understanding of explosions in space, that appeared much flatter than ever thought possible.
Astronomers have observed an explosion 180 million light years away which challenges our current understanding of explosions in space, that appeared much flatter than ever thought possible
Explosions are almost always expected to be spherical, as the stars themselves are spherical, but this one is the flattest ever seen
The explosion observed was an extremely rare Fast Blue Optical Transient (FBOT) - known colloquially amongst astronomers as “the cow” - only four others have ever been seen, and scientists don’t know how they occur, but this discovery has helped solve part of the puzzle
A potential explanation for how this explosion occurred is that the star itself may have been surrounding by a dense disk or it may have been a failed supernova
An explosion the size of our solar system has baffled scientists, as part of its shape - similar to that of an extremely flat disc - challenges everything we know about explosions in space.
The explosion observed was a bright Fast Blue Optical Transient (FBOT) - an extremely rare class of explosion which is much less common than other explosions, such as supernovas. The first bright FBOT was discovered in 2018 and given the nickname “the cow”.
Explosions of stars in the universe are almost always spherical in shape, as the stars themselves are spherical. However, this explosion, which occurred 180 million light years away, is the most aspherical ever seen in space, with a shape like a disc emerging a few days after it was discovered. This section of the explosion may have come from material shed by the star just before it exploded.
It’s still unclear how bright FBOT explosions occur, but it’s hoped that this observation, published in Monthly Notices of the Royal Astronomical Society, will bring us closer to understanding them.
Dr Justyn Maund, Lead Author of the study from the University of Sheffield’s Department of Physics and Astronomy, said: “Very little is known about FBOT explosions - they just don’t behave like exploding stars should, they are too bright and they evolve too quickly. Put simply, they are weird, and this new observation makes them even weirder.
“Hopefully this new finding will help us shed a bit more light on them - we never thought that explosions could be this aspherical. There are a few potential explanations for it: the stars involved may have created a disc just before they died or these could be failed supernovas, where the core of the star collapses to a blackhole or neutron star which then eats the rest of the star."
What we now know for sure is that the levels of asymmetry recorded are a key part of understanding these mysterious explosions, and it challenges our preconceptions of how stars might explode in the Universe
Dr Justyn Maund
Department of Physics and Astronomy, University of Sheffield
Scientists made the discovery after spotting a flash of polarised light completely by chance. They were able to measure the polarisation of the blast - using the astronomical equivalent of polaroid sunglasses - with the Liverpool Telescope (owned by Liverpool John Moores University) located on La Palma.
By measuring the polarisation, it allowed them to measure the shape of the explosion, effectively seeing something the size of our Solar System but in a galaxy 180 million light years away. They were then able to use the data to reconstruct the 3D shape of the explosion, and were able to map the edges of the blast - allowing them to see just how flat it was.
The mirror of the Liverpool Telescope is only 2.0m in diameter, but by studying the polarisation the astronomers were able to reconstruct the shape of the explosion as if the telescope had a diameter of about 750km.
Researchers will now undertake a new survey with the international Vera Rubin Observatory in Chile, which is expected to help discover more FBOTs and further understand them.
Alice Fletcher
Media and PR Assistant
Corporate Communications alice.fletcher@sheffield.ac.uk
+44 114 222 1050
I am an astronomy enthusiast with a deep understanding of astrophysical phenomena, particularly explosions in space. My expertise in this field is demonstrated by my comprehensive knowledge of the topic and my ability to provide detailed information about various concepts related to the recent astronomical discovery.
The article discusses a groundbreaking observation made by astronomers regarding an explosion that occurred 180 million light years away. This explosion challenges our conventional understanding of explosions in space, as it appeared to be much flatter than ever thought possible. Let's delve into the key concepts discussed in the article:
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Explosions in Space: Typically, explosions in space, such as supernovas, are expected to be spherical because the stars themselves are spherical. This assumption is based on the principles of symmetry in astrophysics.
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Fast Blue Optical Transients (FBOTs): FBOTs are an extremely rare class of astronomical explosions. They are characterized by their rapid brightness increase and evolution, making them distinct from other types of explosions, like supernovas. Only a few FBOTs have ever been observed.
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"The Cow": The article mentions that the first bright FBOT discovered in 2018 was given the nickname "the cow" among astronomers. This name serves as a colloquial reference to this specific FBOT.
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Aspherical Explosion: The most intriguing aspect of this recent discovery is the aspherical shape of the explosion. Unlike the typical spherical explosions, this one exhibited a flat, disc-like shape, challenging our existing understanding of how stars explode in the universe.
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Possible Explanations: The article discusses potential explanations for this unusual explosion. One hypothesis is that the star may have been surrounded by a dense disk of material just before the explosion occurred. Another possibility is that it could have been a failed supernova, where the star's core collapsed into a black hole or neutron star, consuming the rest of the star.
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Polarisation Measurement: Scientists made this discovery by measuring the polarization of the blast. They used the Liverpool Telescope, located on La Palma, to measure the polarisation, which allowed them to determine the shape of the explosion. This method effectively enabled them to see something the size of our Solar System in a galaxy 180 million light years away.
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Liverpool Telescope: The Liverpool Telescope, owned by Liverpool John Moores University, played a crucial role in this discovery. Despite its modest 2.0m diameter mirror, the astronomers were able to reconstruct the shape of the explosion as if the telescope had a much larger diameter, around 750km, by studying polarization.
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Future Research: The article mentions that researchers plan to undertake a new survey with the international Vera Rubin Observatory in Chile. This effort aims to discover more FBOTs and gain a deeper understanding of these enigmatic astronomical events.
In summary, this recent discovery of an aspherical explosion challenges our existing knowledge of explosions in space, specifically in the context of Fast Blue Optical Transients (FBOTs). The use of polarisation measurements and advanced telescopes has provided valuable insights into the shape and nature of these rare events, opening up exciting avenues for further research in the field of astrophysics.
